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Specifying the Enterprise and Information Viewpoints for a Corporate Spatial Data Infrastructure using ICA’s Formal Model Italo L. Oliveira 1 , Jugurta Lisboa-Filho 1 , Carlos A. Moura 2 , Alexander G. Silva 2 1 Department of Informatics, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil [email protected], [email protected] 2 Companhia Energética de Minas Gerais (CEMIG), Belo Horizonte MG Brazil [email protected], [email protected] Keywords: Spatial Data Infrastructure, RM-ODP, Enterprise Viewpoint, Information Viewpoint Abstract: The International Cartographic Association (ICA) has proposed a formal model to describe Spatial Data Infrastructure (SDI) using three of the five viewpoints of the RM-ODP (Reference Model for Open Distributed Processing) framework, which was later adapted by other researchers. However, the adapted ICA model has not been validated for corporate-level SDI. The Companhia Energética de Minas Gerais (Minas Gerais Power Company - Cemig) seeks to develop an SDI to aid in discovering and reutilizing spatial data within and outside the corporation. The present study aimed to assess the use of the model proposed by the ICA to specify corporate-level SDI using SDI-Cemig as a case study by describing the viewpoints Enterprise and Information. These viewpoints from the adapted ICA model have proved appropriate to describe SDI-Cemig, whose differences are due to the SDI’s peculiarities. Although a single study cannot validate the ICA model for a whole SDI level, this research shows that the adapted ICA model can be used to describe the viewpoints Enterprise and Information in corporate SDI. 1 INTRODUCTION Geospatial data are those referenced in relation to the ground surface and are essential to aid in an organization’s decision-making and planning. However, according to Nebert (2004) and Rajabifard and Williamson (2001), geospatial data are a costly resource both in time and money involved in surveying them. In order to cut down the costs associated with using and obtaining geospatial data, the Spatial Data Infrastructure (SDI) concept was created. There are several definitions for SDI. Rajabifard and Williamson (2001) define SDI as an environment in which the users reach their goals by using technologies and collaboration. Harvey et al. (2012) consider the SDI a concept that aids in sharing data and geospatial services among different users of a given community. In order to help share and discover geospatial data and services, the SDIs are organized hierarchically. Figure 1 presents the SDI hierarchy and the nomenclatures used in the present study. According to Hjelmager et al. (2008), the SDI concept is very broad and leads to different forms of development both at the organizational and technical level, as pointed out by Cooper et al. (2013). Thus, the International Cartographic Association (ICA) has developed a model to describe SDI regardless of the technologies or implementations (Hjelmager et al., 2008), a concept that was later extended by Cooper et al. (2011); Béjar et al. (2012); Cooper et al. (2013); and Oliveira and Lisboa-Filho (2015). However, the use of ICA’s formal model for SDI has not been evaluated to develop corporate-level SDI yet. The Companhia Energética de Minas Gerais (Cemig) is a mixed-economy company acting in the electricity sector composed of over 200 partners and controlled by the government of the state of Minas Gerais (Brazil). Cemig seeks to develop an SDI, named SDI-Cemig, to standardize the processes that use the company’s geospatial data, thus helping such data be shared and surveyed.

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  • Specifying the Enterprise and Information Viewpoints for a

    Corporate Spatial Data Infrastructure using ICA’s Formal Model

    Italo L. Oliveira1, Jugurta Lisboa-Filho1, Carlos A. Moura2, Alexander G. Silva2 1 Department of Informatics, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil

    [email protected], [email protected]

    2Companhia Energética de Minas Gerais (CEMIG), Belo Horizonte – MG – Brazil

    [email protected], [email protected]

    Keywords: Spatial Data Infrastructure, RM-ODP, Enterprise Viewpoint, Information Viewpoint

    Abstract: The International Cartographic Association (ICA) has proposed a formal model to describe Spatial Data

    Infrastructure (SDI) using three of the five viewpoints of the RM-ODP (Reference Model for Open

    Distributed Processing) framework, which was later adapted by other researchers. However, the adapted

    ICA model has not been validated for corporate-level SDI. The Companhia Energética de Minas Gerais

    (Minas Gerais Power Company - Cemig) seeks to develop an SDI to aid in discovering and reutilizing

    spatial data within and outside the corporation. The present study aimed to assess the use of the model

    proposed by the ICA to specify corporate-level SDI using SDI-Cemig as a case study by describing the

    viewpoints Enterprise and Information. These viewpoints from the adapted ICA model have proved

    appropriate to describe SDI-Cemig, whose differences are due to the SDI’s peculiarities. Although a single

    study cannot validate the ICA model for a whole SDI level, this research shows that the adapted ICA model

    can be used to describe the viewpoints Enterprise and Information in corporate SDI.

    1 INTRODUCTION

    Geospatial data are those referenced in relation to

    the ground surface and are essential to aid in an

    organization’s decision-making and planning.

    However, according to Nebert (2004) and Rajabifard

    and Williamson (2001), geospatial data are a costly

    resource both in time and money involved in

    surveying them. In order to cut down the costs

    associated with using and obtaining geospatial data,

    the Spatial Data Infrastructure (SDI) concept was

    created.

    There are several definitions for SDI. Rajabifard

    and Williamson (2001) define SDI as an

    environment in which the users reach their goals by

    using technologies and collaboration. Harvey et al.

    (2012) consider the SDI a concept that aids in

    sharing data and geospatial services among different

    users of a given community.

    In order to help share and discover geospatial

    data and services, the SDIs are organized

    hierarchically. Figure 1 presents the SDI hierarchy

    and the nomenclatures used in the present study.

    According to Hjelmager et al. (2008), the SDI

    concept is very broad and leads to different forms of

    development both at the organizational and technical

    level, as pointed out by Cooper et al. (2013). Thus,

    the International Cartographic Association (ICA) has

    developed a model to describe SDI regardless of the

    technologies or implementations (Hjelmager et al.,

    2008), a concept that was later extended by Cooper

    et al. (2011); Béjar et al. (2012); Cooper et al.

    (2013); and Oliveira and Lisboa-Filho (2015).

    However, the use of ICA’s formal model for SDI

    has not been evaluated to develop corporate-level

    SDI yet. The Companhia Energética de Minas

    Gerais (Cemig) is a mixed-economy company

    acting in the electricity sector composed of over 200

    partners and controlled by the government of the

    state of Minas Gerais (Brazil). Cemig seeks to

    develop an SDI, named SDI-Cemig, to standardize

    the processes that use the company’s geospatial data,

    thus helping such data be shared and surveyed.

  • Figure 1: SDI hierarchy – Adapted from Rajabifard and

    Williamson (2001) and Crompvoet (2001).

    The present study presents the use of ICA’s

    formal SDI model under SDI-Cemig’s specification

    while detailing the viewpoints Enterprise and

    Information and verifying whether this model allows

    a corporate SDI to be appropriately described.

    The remaining of the paper is structured as

    follows. Section 2 describes ICA’s formal SDI

    model, detailing the viewpoints Enterprise and

    Information of an SDI. Section 3 presents the

    specification of the viewpoints Enterprise and

    Information for SDI-Cemig. Section 4 discusses the

    results found in the present research, while Section 5

    presents some final considerations of the study.

    2 ICA’S FORMAL MODEL

    According to Hjelmager et al. (2008), ICA’s formal

    SDI model (henceforth called only formal model) is

    a model that describes SDI regardless of

    technologies, policies, or implementations. In order

    to describe SDI, the ICA chose to use the RM-ODP

    (Reference Model for Open Distributed Processing)

    framework.

    RM-ODP is an architectural framework

    standardized by the International Organization for

    Standardization/International Electrotechnical

    Commission (ISO/IEC) that is able to describe

    heterogeneous distributed processing systems by

    using viewpoints (Farooqui, Logrippo and de Meer,

    1995).

    According to Raymond (1995), the use of the

    viewpoint concept allows describing complex

    distributed systems as smaller models, each of which

    describes different relevant issues to different users

    of the system. RM-ODP uses the following

    viewpoints: Enterprise, Information, Computation,

    Engineering, and Technology. Figure 2 presents the

    five viewpoints and the relationship among them.

    Figure 2: RM-ODP framework viewpoints – Adapted

    from Hjelmager et al. (2008).

    The viewpoint Enterprise describes the system’s

    policies, scope, goal, and requirements for the

    organization. The viewpoint Information details the

    data semantics and the behavior in the system,

    whose behavior will be restricted/determined by the

    policies defined in the viewpoint Enterprise

    (Farooqui, Logrippo and de Meer, 1995) (Hejlmager

    et al., 2008). According to Cooper et al. (2013), the

    viewpoint Computation describes the components

    that make up the system and their interactions

    through the interface with no concern about the

    components’ physical distribution. The viewpoint

    Engineering, according to Farooqui, Logrippo and

    de Meer (1995), “identifies the requirements and

    features needed for the system to support the model

    described in the viewpoint Computation.” Finally,

    the viewpoint Technology details the technological

    devices used by the system.

    ICA’s formal model describes only the

    viewpoints Enterprise, Information, and

    Computation. According to Hjelmager et al. (2008),

    the viewpoints Engineering and Technology heavily

    depend on the implementation and are not

    considered in ICA’s model. The viewpoints

    Enterprise and Information will be described in the

    sub-sections below. The viewpoint Computation will

    not be described since it is not relevant for this

    study.

    2.1 Enterprise Viewpoint

    The viewpoint Enterprise, according to

    Hjelmager et al. (2008), describes the actors and the

    relation among the different parts of the system.

    Figure 3 shows the relationship among the

    different compounds that make up the SDI through a

    diagram of UML classes. In the diagram, the SDI is

    the central compound and its attributes are the scope

    and a plan for its implementation. An SDI is formed

    by products, which are in turn formed by geospatial

    data and services from the SDI. The acquisition and

    use of these products is the reason why a user will

  • use the SDI. Hence, the Product can be considered

    the core part of the SDI (Hjelmager et al., 2008).

    The Metadata will describe and be used by the

    Product, and will be managed by the Processing

    Tools to aid in the discovery and use of geospatial

    data and services. The component Processing Tools

    represents the systems that carry out some sort of

    geospatial data processing and will connect to the

    SDI through the component Connectivity, which will

    use a certain Technology to perform its role.

    Figure 3: Components that make up an SDI – Hjelmager et al. (2008).

    According to Hjelmager et al. (2008), the

    component Policies is responsible for defining the

    policies that will restrict and determine the SDI’s

    functioning and evolution. Although this component

    is represented by a single class, the component

    Policies may be specialized into several other

    classes, which will be shown ahead.

    The actors are individuals with a stake on the

    SDI’s success and may use it or contribute to it.

    Hjelmager et al. (2008) defined five main actors for

    the SDI, which were expanded by Cooper et al.

    (2011) and Béjar et al. (2012). However, there are

    differences in semantics and terminology between

    the actors by Hjelmager et al. (2008) and Cooper et

    al. (2001) and those proposed by Béjar et al. (2012).

    This same characteristic holds true regarding the

    SDI’s policies.

    Oliveira and Lisboa-Filho (2015) unified the

    actors and policies proposed by the ICA with those

    proposed by Béjar et al. (2012). This way, the

    designers that may use ICA’s model will have a

    single set of possible actors and policies, which

    facilitates communication and knowledge exchange

    among designers.

    Figure 4 presents the six main actors an SDI may

    have: User; Producer; Operational Body; Governing

    Body; Broker; Value-Added Reseller; and Provider.

    According to Oliveira and Lisboa-Filho (2015),

    the User is the actor that will use the resources

    offered by the SDI to reach his or her goals. The

    Producer is responsible for producing the SDI’s data

    and services while the Provider makes these data

    and services available. The Governing Body is

    responsible for the SDI’s administration and its

    attributions include creating, changing, and

    removing policies. The Broker’s role is to aid in the

    negotiations between providers and users. The

    Value-Added Reseller (VAR) modifies an existing

    product and makes it available in the SDI as a new

    product. Finally, the Operational Body is

    responsible for all the technical side of the SDI’s

    functioning. All actors are specialized to describe

    their attributions in more details. The specializations

    can be found in Oliveira and Lisboa-Filho (2015).

    Table 1 presents the policies unified by Oliveira

    and Lisboa-Filho (2015). The policies were

    specialized into: Business Model, Promotion,

    Standards, Education, and Constraints. The

  • descriptions and specializations of each type are

    shown in Table 1.

    2.2 Viewpoint Information

    According to Hjelmager et al. (2008), the viewpoint

    Information in the RM-ODP framework describes

    the system data, from their semantics to their

    behavior, which are regulated by the policies defined

    in the viewpoint Enterprise. In the case of an SDI,

    Hjelmager et al. (2008) consider as data the products

    offered by the SDI, i.e., the geospatial data and

    services.

    Figure 5 describes the relationship of the

    products with the other SDI components using the

    UML class diagram. The class Product, for being

    the most relevant object in the viewpoint

    Information, is the center of the diagram. The class

    Policies represents the policies defined in the

    viewpoint Enterprise, which will restrict and target

    the product specifications, which are represented by

    the class Product Specification (Hjelmager et al.,

    2008).

    Figure 4: Main actors of an SDI after the unification –

    Oliveira and Lisboa-Filho (2015).

    Table 1: SDI policies after the unification – Oliveira and Lisboa-Filho (2015).

    Policies Description

    Business

    Model

    Governance Determines the decision-making process

    Regulates the policy-creation process

    Membership Determines the relationships among the SDI members

    Quality Defines the quality levels established in the SDI

    Access Determines how the SDI products can be accessed and who can do it

    Role Assignment Defines the responsibilities (actor roles) of the SDI users

    Funding Defines how the resources will be forwarded to develop and maintain the SDI

    Promotion - How the SDI will be advertised

    Standards - Defines the standards adopted by the SDI

    Foundation Defines the main SDI products

    Education - Determines the trainings the SDI users may take part in

    Best Practices Practices that must be adopted by the users member of the SDI

    Constraints

    Legal Constraints Restrictions imposed by local laws of where the SDI is located

    Business

    Agreements Restrictions existing due to contract between companies

    The Products are described by the metadata

    (class Metadata) and both are recorded in catalogs

    (class Catalog), which may contain other catalogs to

    allow for a hierarchy to be created. The products can

    be classified into ervices and data (either geospatial

    or not). The data are used, aided by previous

    knowledge, as a source of information, which may

    generate new knowledge (Hjelmager et al., 2008).

    3 SDI-CEMIG

    As specified in Section 1, Cemig seeks to develop an

    SDI to help share and use geospatial data in the

    companies that make up the conglomerate. The

    model adapted from the ICA was used to specify the

    SDI-Cemig so as to guarantee that the basic SDI

    concepts in the literature would be contemplated

    during the specification phase. The sub-sections

    below describe the viewpoints Enterprise and

    Information of SDI-Cemig.

  • Figure 5: Class diagram for the viewpoint information – Hjelmager et al. (2008).

    3.1 Viewpoint Enterprise

    As described in sub-section 2.1, the ICA has

    described the parts that make up the SDI and the

    possible actors that may interact with it. The

    components and actors were identified in SDI-

    Cemig to check whether they properly describe

    corporate SDI.

    3.1.1 Components of SDI-Cemig

    The SDI is considered the central element in

    Figure 3 and has a scope and implementation plan

    (Hjelmager et al., 2008). The scope of SDI-Cemig is

    to make available online a set of geospatial layers

    considered essential to the companies in the electric

    sector and that may be used by Cemig’s employees

    and clients, besides offering services to visualize and

    discover geospatial data. The implementation plan of

    SDI-Cemig will be publicized by the end of the

    SDI’s development.

    The component Product is made up of the SDI’s

    geospatial data and services. SDI-Cemig has the data

    of the geospatial layers considered basic for Cemig,

    i.e., they are essential layers to the working of the

    processes that involve geospatial data and are

    described by the Foundation policies and detailed in

    the conceptual model in sub-section 3.2.1.

    SDI-Cemig must provide services for the

    discovery, visualization, and recovery of geospatial

    data, which must be compatible with the OGC

    standards. The use of services based on the OGC

    standards allows SDI-Cemig to interact with other

    SDIs at different levels, such as the INDE

    (Infraestrutura Nacional de Dados Espaciais –

    National Spatial Data Infrastructure), the INSPIRE

    (Infrastructure for Spatial Information in the

    European Community), and the CGDI (Canadian

    Geospatial Data Infrastructure). For a new service to

    be considered compatible with the OGC standard, its

    operations must follow the specifications proposed

    in the documents provided by the OGC.

    Although Figure 3 shows that the component

    Product is self-related, since a service may generate

    new data, SDI-Cemig has no processing service able

    to produce new geospatial data at first.

    The SDI products will be described by Metadata,

    which are specified according to the Metadata

    Geospatial do Brasil (Geospatial Metadata of Brazil

    - MGB) profile (CONCAR, 2009). The MGB profile

    defines the elements existing in the metadata that

    describe the geospatial data to be introduced into the

    INDE.

    The metadata may be used by the Processing

    Tools to help discover new geospatial data and

    services and to obtain relevant information on them,

    e.g., which features are offered by the services and

    in which format the geospatial data is being made

    available. In SDI-Cemig, the Processing Tools are

    the legacy systems and desktop applications that use

    the SDI’s geospatial data and services. Cemig has

    several applications and legacy systems to process

    geospatial data that are very important in the

    company’s processes. The component Connectivity specifies how the

    Processing Tools interact with the SDI, which is possible by using a Technology. Cemig’s legacy systems and desktop applications interact with SDI-

  • Cemig by exchanging files in the XML format using the GML standard as schema. Besides using files, the desktop applications can interact with SDI-Cemig through web services in case they are supported.

    SDI-Cemig specifies at least one policy for each

    type present in Table 1, except for Governance and

    Business Agreements, which have no policy defined

    yet. The policies will not be presented due to space

    constraints. However, some policies will be pointed

    out along the text.

    3.1.2 Communities and Roles in SDI-Cemig

    Besides the components in SDI-Cemig, the

    viewpoint Enterprise specifies the communities that

    make up the SDI and the possible roles they may

    play to reach their goals.

    A community is a concept of RM-ODP and is a

    set of one or more entities that have similar behavior

    and seek to reach a given common goal (Linington

    et al., 2011). The behavior the communities may

    take on are described through roles to facilitate them

    being reused. In the case of SDI-Cemig, the possible

    roles the communities may take on were described

    by Hjelmager et al. (2008), Cooper et al. (2011), and

    Béjar et al. (2012), were adapted and unified by

    Oliveira and Lisboa-Filho (2015), and are used to

    specify the communities.

    Figure 6: Community Committee and its respective roles.

    According to Linington et al. (2011), a

    community is specified by the roles it can take on,

    its possible behaviors, the enterprise objects it uses,

    and the goal it must reach. This sub-section,

    however, details only the roles they may take on and

    whether these roles match the roles unified by

    Oliveira and Lisboa-Filho (2015). Figures 6, 7, 8, and 9 present the communities

    identified in Cemig’s environment and the roles they may take on when interacting with SDI-Cemig. In

    Figure 6, the community Committee is formed by members of different sectors at Cemig, represented by the communities Representative, such as Information Technology (IT) and the sectors Generation, Transmission, and Distribution, and its attribution is to define the working of certain processes carried out by these sectors. Hence, the Committee takes on the roles of Legislator, Secretariat, and Policy Maker and is responsible for all of SDI-Cemig’s administrative area.

  • The community GIS Analyst (Figure 7) represents the IT individuals with positions homonymous to the community, who are responsible for carrying out and analyzing the procedures performed in a Geographic Information System (GIS) to manipulate geospatial data.

    As shown in Figure 7, the Geoprocessing Analyst

    may take on the roles of Data/Service Distributor,

    Data and Metadata Aggregator/Integrator, and

    Négociant. The community is responsible for

    providing the geospatial data and services produced

    by the Producers in SDI-Cemig.

    The community is also responsible for

    purchasing the geospatial data the users require, then

    acting as a Négociant. Finally, the Geoprocessing

    Analyst, when carrying out procedures on the

    geospatial data in a GIS, is able to generate new

    geospatial data or to expand existing data, thus

    taking on the role of Data and Metadata

    Aggregator/Integrator. Moreover, the IT will be in

    charge of creating and maintaining the catalogs of

    data and services made available by SDI-Cemig by

    using user-produced metadata.

    Cemig has several sectors that act in the

    processes of electric energy generation,

    transmission, and distribution. The generation

    process consists in the generation of electricity

    through power plants and Cemig has hydroelectric,

    thermal, wind, and solar plants. Transmission

    consists in a network that carries the energy

    produced by the power plants to the large consuming

    centers. Finally, distribution is the network that

    serves energy to small- and medium-sized

    companies and to residential consumers (Leão,

    2009).

    The generation, transmission, and distribution

    groups are represented in Figure 8 by packages

    comprising all the sectors related to each group.

    Since there is a large number of sectors related to

    each group, they are represented by the communities

    Generation, Transmission, and Distribution. Besides

    these communities, each group has a Geospatial

    Data Manager and a Representative.

    Each group has its Spatial Data Manager

    community, which is responsible for guaranteeing

    data consistency for each group, hence it takes on

    the role of Database Administrator. However, it

    must be pointed out that Cemig has a position called

    Database Administrator, although its role is different

    from the one defined by Cooper et al. (2011). At

    Cemig, the position Database Administrator is in

    charge of guaranteeing that the database and the

    hardware supporting it are in order.

    The community Representative is a generic

    community used to illustrate the individuals that

    represent the interests of each group in the

    community Committee. Finally, each group has a

    homonymous community (Generation,

    Transmission, and Distribution) that represents the

    different sectors at Cemig that work directly or

    indirectly with the data of that group. The

    communities Generation, Transmission, and

    Distribution are considered Official Production

    Agencies since they are the main data producers in

    SDI-Cemig and since their sectors belong to Cemig.

    These communities are also responsible for

    publicizing the data they produce in the SDI, thus

    taking on the role of A Producer that is its own

    Data/Service Provider.

    SDI-Cemig interacts with other communities

    besides those within Cemig itself by interacting with

    other SDIs and organizations, as shown in Figure 9.

    The community of the Instituto Brasileiro de

    Geografia e Estatística (Brazilian Institute of

    Geography and Statistics - IBGE) is the federal

    public organ that produces nationwide geospatial

    data, besides being responsible for defining the

    standards to be used by the other geospatial-data-

    producing organizations, thus taking on the role of

    Producer. The data produced by the IBGE are

    publicized through the INDE. SDI-Cemig interacts

    with the INDE and recovers the data available

    through web services, which makes the INDE a

    Provider of SDI-Cemig.

    Besides the INDE, SDI-Cemig will obtain and

    publicize information to the Sistema de Informações

    Geográficas do Setor Elétrico (Geographic

    Information System of the Power Sector - SIGEL)

    belonging to the Agência Nacional de Energia

    Elétrica (National Electric Energy Agency -

    ANEEL). ANEEL is responsible for regulating and

    overseeing the Brazilian electric energy market to

    guarantee that the companies working in the country

    follow the regulations in effect. The SIGEL is a

    system that allows the visualization and obtention of

    some geospatial data made available by the utility

    companies to ANEEL. Therefore, ANEEL takes on

    the role of User in SDI-Cemig by recovering the

    data through the GeoPortal or through web services,

    while the SIGEL takes on the role of Data Provider

    by making available to SDI-Cemig the data provided

    to ANEEL by the other utility companies.

  • Figure 7: Geoprocesing Analyst Community and its respective roles.

    3.2 Viewpoint Information

    As well as in the viewpoint Enterprise, the

    components defined by Hjelmager et al. (2008) for

    the viewpoint Information, shown in Figure 5 in sub-

    section 2.2, are identified in SDI-Cemig.

    According to Linington et al. (2011), the

    viewpoint Information is responsible for “modeling

    the shared information that is handled by the

    system.” Therefore, the invariant scheme of the

    geospatial database used in SDI-Cemig is modeled.

    The dynamic and static schemes are not modeled

    because SDI-Cemig, having only geospatial data,

    contains little or no dynamically generated data due

    to an action. When geospatial data are represented in

    alphanumeric format, comparing them to the original

    data to check whether the representation is

    consistent becomes difficult.

    According to Hjelmager et al. (2008), the model

    presented in Figure 5 begins with the component

    Policies, which defines the basic geospatial data

    (layers) the SDI must have, besides allowing the link

    with the viewpoint Enterprise. The basic data SDI-

    Cemig has are described in the policies Foundation.

    It must be pointed out that much of the data in SDI-

    Cemig are related to the electricity generation,

    transmission, and distribution.

    The members of SDI-Cemig may request new

    products (data and services) by opening a ticket with

    Cemig’s helpdesk, being limited by the policies.

    Such tickets are considered the products’

    specifications (component Product Specification).

    The Products are described by Metadata, which

    allows the users to assess whether the product meets

    their needs, besides facilitating searching for them.

    According to the policy Legal Constraints “Adoção

    do Decreto de Lei Nº 6.666 – Uso do perfil MGB

    para a documentação de metadados geoespaciais

    produzidos em território nacional,” the products in

    SDI-Cemig will be described using metadata

    documented following the specification of the MGB

    profile (CONCAR, 2009).

    Both Metadata and Products will be recorded in

    a Catalog to aid in their discovery. The catalogs will

    be created according to the topics of the geospatial

    data offered by SDI-Cemig such as hydrography,

    generation, transmission, distribution, infrastructure,

    etc. According to the model in Figure 5, the data

    generate information based on pre-established

    knowledge. In SDI-Cemig, the data are used to

    generate information used by the different sectors at

    Cemig through reports and maps. Such information

    is generated based on the knowledge of employees

    specialized in geoprocessing, usually Geoprocessing

    Analysts.

  • Figure 8: Groups Generation, Transmission, and Distribution with their respective communities and roles.

    3.2.1 Conceptual Database Modeling

    According to Béjar et al. (2012), the policies of

    the type Foundation define the basic data and

    services the SDI must have. However, only the

    database description is not able to show the

    relationship among the data or how they will behave

    in the system, which is one of the goals the

    viewpoint Information aims to represent.

    Figure 10 presents the conceptual scheme of the

    database adopted by SDI-Cemig. Due to space

    constraints, only the layers related to electricity

    generation, transmission, and distribution will be

    represented.

    The UML class diagram extended with

    geographical and topological builders of the OMT-G

    (Borges, Davis Jr. and Laender, 2001) was used to

    create the scheme.

    The package Distribution Grid has layers related

    to Cemig’s regional distribution grid and layers that

    help manage this grid. The layer

    Malha_Regional_Distribuicao represents the limit

    of the distribution areas, which contain a

    headquarters (Malha_Regional_Sede) inside them.

    The business units (Unidades_Negocio) are areas

    defined according to the type of business Cemig

    intends to establish in a given region, which aids in

    planning and in the decision-making process. As

    well as the regional grid, the business units have a

    headquarters (Unidades-Negocio_Sede).

    The area where Cemig can work in the state of

    Minas Gerais, negotiated with the state’s

    government, is represented by the class

    Areas_Concessao_Distribuicao, while the class

    Local_Cemig_Concessao represents the area where

    Cemig is currently working. To help in the decision-

    making process, Cemig has divided the state of

    Minas Gerais into several regions called

    transmission regions (Regionais_Transmissao). As

    well as the distribution grid, the transmission regions

    are divided according to criteria that meet the

    company’s business rules.

    The packages Generation, Transmission, and

    Distribution contain the classes that represent the

    elements that make up the electric grid administered

    by Cemig. Cemig’s electric grid nodes comprise

  • structures, namely Estruturas_LT for Generation,

    Estrutura_LT_230-500 for Transmission, and

    Estrutura_LT_34-161 for Distribution. The classes

    Vao_LT, Vao_LT_230-500, and Vao_LT_34-161

    represent, respectively, the arcs of Generation,

    Transmission, and Distribution.

    Figure 9: External communities that interact with SDI-Cemig.

    The structures that make up the Generation

    nodes comprise power plants, which can be

    hydroelectric, wind, or solar (Usinas_Hidreletricas,

    Usinas_Eolicas, Usinas_Solares, respectively), and

    by Centrais_Geradoras_Hidreletricas, Subesta-

    coes_Geracao, and Pequenas_Centrais_Hidre-

    letricas. Although it is said in the subsection 3.1.2

    that Cemig owns thermal power plants, they are not

    considered, at the first moment, in the conceptual

    model.

    In Transmission, the only structures that make up

    the network are the transmission sub-stations

    (Subestacoes_Transmissao). In Distribution, the

    structures comprise Postes (poles) and

    Subestacoes_Distribuição. The poles may have a

    transformer. Generation, Transmission, and

    Distribution have, respectively, the classes

    Linhas_Transmissao, Linhas_Transmissao_230-500,

    and Linhas_Transmissao_34-161. These classes are

    used to identify a portion of the network, which

    must comprise at least an arc and its respectively

    beginning and end nodes.

    4 DISCUSSION OF RESULTS

    The adapted ICA model proved appropriate to

    describe the viewpoints Enterprise and Information

    of SDI-Cemig. The differences found between the

    model and the specification are due to the specific

    characteristics of SDI-Cemig.

    One such difference is that there are no

    geoprocessing services. In the viewpoint Enterprise,

    the lack of geoprocessing services impacts the

    component Product, which cannot be self-related.

    In addition, the existence of the component

    Technology in ICA’s formal model contradicts the

    goal of the viewpoint Enterprise in the RM-ODP

    framework, which is to describe the system’s scope,

    policies, and requirements. This contradiction can be

    extended to the component Connectivity, however,

    further studies are needed to state that.

    Also regarding the viewpoint Enterprise, during

    the specification of the actors in SDI-Cemig, the

    concentration of positions in the IT community

    becomes visible, which are responsible for providing

    data to SDI-Cemig, performing maintenance in

    smaller systems, negotiating new geospatial data,

    and creating new policies. Many of these

    responsibilities are beyond the scope IT should take

    on in SDI-Cemig.

  • Figure 10: Layers related to the electric system and the distribution grid of the state of Minas Gerais from the conceptual scheme of SDI-Cemig’s database.

  • Regarding the policies, the ones related to the

    type Governance have not been defined yet.

    Moreover, other types of policies have a small

    number of policies specified (usually a single policy

    has been specified for each type).

    The viewpoint Information of SDI-Cemig has all

    the components specified by the adapted ICA model,

    with no need to change their behavior or semantics.

    Although the adapted ICA formal model

    describes SDI at all levels and, thus, guarantees the

    basic concepts in the literature are contemplated in

    the specification phase, there is no description of

    how the model should be used. For instance, how

    many details are required to describe the

    components of the viewpoint Enterprise, or what

    could be considered a product specification?

    5 FINAL CONSIDERATIONS

    Using the adapted ICA formal model allows the key

    components of an SDI to be contemplated in the

    design phase, besides allowing a better

    understanding of the basic concepts such as the SDI

    structure, who the users will be and what roles they

    will take on when using an SDI, how the policies

    will impact the SDI development, etc.

    The viewpoints Enterprise and Information in

    ICA’s formal model properly describe these

    viewpoints in SDI-Cemig and, although the

    specification of a single corporate SDI does not

    ensure the model will be applicable at any corporate

    level, it does indicate the viewpoints Enterprise and

    Information in ICA’s formal model can be applied to

    other corporate SDIs. Moreover, the present study

    may help other designers wanting to use ICA’s

    model to specify new SDIs regardless of their level.

    As future works, we intend to specify the

    viewpoint Computation in SDI-Cemig to verify

    whether it is in accordance with the viewpoint

    Computation specified in the adapted ICA model.

    Acknowledgements

    This project was partially funded by the Brazilian

    research promotion agencies Fapemig and CAPES,

    along with Cemig Enterprise.

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